Hard core bowling pin or the like



Fell 8, 1966 F. E. sATcHELl. ETAL 3,233,903

HARD CORE BOWLING PIN OR THE LIKE Filed March 27, 1965 l Il li ll INVNTORs: goza@ d United States Patent C) 3,233,903 HARD CORE BOWLING PIN GR THE LIKE Fred E. Satchell, Grand Haven, and Louis J. Trier and John J. Weisz, Muskegon, Mich., assiguors to Brunswick Corporation, a corporation of Delaware Filed Mar. 27, 1963, Ser. No. 268,275 5 Claims. (Cl. 273-82) This invention relates to an article having a hard core and intended for use under conditions wherein the `core is subjected to impact forces. More particularly, this invention relates to bowling pins and scoring characteristics thereof.

It is a general object of this invention to provide new and useful hard core articles of manufacture.

It is another object of this invention to provide new and useful bowling pins having adjusted scoring characteristics.

Still another o-bject of this invention is to provide a bowling pin having a hard core with a flexible coating on the core and .a generally circumferential comparatively void space between the core and coating at the impact area of the pin.

In one aspect of this invention, it has been an object to provide a -bowling pin in accordance with the foregoing objects wherein the space provided between the core and coating is .a substantially continuous pocket in the" belly region of the pin. Features of such a 4bowling pin provided in accordance with this aspect of the invention may include a circumferential groove in the hard core of the bowling pin and on the exterior core surface which is spanned by the pin coating to define a circumferential continuous air pocket.

In another aspect of this invention, it has been an object to provide a bowling pin in accordance with the penultimate object above wherein the void space is formed by a non-structural very low density foam material disposed between the core and coating and containing a plurality of pockets within the foam which may be destroyed by destroying the foam matrix in situ between the coating and core after the coating is applied. Features of such a bowling pin in accordance with this aspect of the invention may include a generally cylindrical outer surface on the hard core in the belly region across the impact area on which the foam material is secured with the coating on the pin core being applied as a contiinuous coating over the foam, the foam being of very low density but of strength and configuration sufficient to support the coating layers during their application to provide an outer coating surface which is curviplanar and of normal pin contiguration throughout the lbelly region.

It is still a further object of this invention to provide a bowling pin in accordance with t-he foregoing objects wherein the hard core is of a material other than maple wood, such as a hollow metal core, and the space provided between the core and coating is suiiicient to adjust the scoring characteristics of the bowling pin closer -to those of the maple core pin, e.g., by improving scorea'bility of the pin during thin and heavy hits in bowling.

Further objects will become readily apparent from the following detailed description taken in connection with the accompanying drawings, in which:

FIGURE 1 is a Vertical section through an embodiment of a bowling pin of this invention; and

FIGURE 2 is a vertical section through another embodimcnt of a bowling pin o-f this invention.

While illustrative embodiments of the invention are shown in the drawings and will be described in detail herein, the invention is susceptible of embodiment in many diiferent forms, and it should be understood that the present disclosure is to be considered as an exemplication CII ICC

of the principles of the invention and is not intended to limit the scope to the embodiments illustrated.

Illustrative of articles of manufacture having hard cores which receive impacts in use are bowling pins provided by the present invention which are intended to be used in bowling games, such as tenpins, and are to be struck by a ball in the manner normally -occurring during such bowling games. In view of the general symmetry of such bowling pin-s, it is readily understood that during a bowling game the various points or areas of impact of a bowling ball against a standing pin differ merely circumferentially depending upon the orientation of the pin with respect to the ball. Thus, the impact points will fall upon an imaginary plane through the belly 0f the pin and the actual areas of contact of the ball with the pin, assuming some flattening of the ball or pin during impact, will fall in a surface area band around the pin which includes the imaginary plane, the width of the band depending, in addition to other factors, upon the amount of deformation or indentations of the pin or Iball surface under impact conditions.

It is common in the art to refer to the various portions of a bowling pin in terms of the head, neck, shoulder, belly, base, or the like. The belly portion of the bowling pin has been referred to hereinabove, and the should-er and base portions may also be more particularly lreferred `to herein. Turning to the drawings, in FIGURES 1 and 2, the general shoulder areas of the respective pins 10 and 2t? have been generally designate-d by reference numerals 12 and 22, the :belly areas or portions by reference numerals 13 and 23, and the base portions by reference numerals 14 and 24, in order to give a convenient reference to the portions of the pins referred to.

Referring now more particularly to the drawing, there is illustrated in FIGURE 1 an embodiment of this invention wherein a circumferential pocket means 'between the coating and core is defined by a circumferential groove in the core spanned by the coating in the belly region of the pin. The bowling pin is indicated generally by reference numeral 10 and has a hard hollow metal core 11 made of a hard material, for example, a lightweight metallic material such as aluminum, magnesium, alloys of aluminum, alloys of magnesium, a high-impact plastic material such as high-impact polystyrene, polyesters and the like. Of course, it is to be understood that core 11 may be a solid core if desired and/or may be formed of maple or other wood such `as beech or pecan.k Other usable hard core materials may be apparent to those in the art. In the illustrated embodiment, core 11 is provided with an interna-l brace means in the form of an annular rib 15 extending inwardly from the core in the belly portion of the core at approximately the area of major ball impact forces against the core.

vCircumferential pocket means are provided in the bowling pin 10 by means of the circumferential groove 16 around the belly region of the pin opposing circumfer- -ential rib 15. Rib 15 may be omitted, if desired. Groove 16 is of substantially uniform depth in the outer -surface of the core. Core 11 is covered by coating 17 which is a resilient elastomeric composition. Coating 17 spans groove 16 defining an annular space 18 within the groove and between core 11 and coating 17. Although groove 16 is shown as a vertical walled groove, `any configuration of recess may be substituted therefor, if desired, e.g. gradual inward deviations of the core in the belly region may form the walls of the groove. Alternatively, the void may be a recess in the coating 17 at the core surface.

.Ei The resilient elastomeric composition of coating 17 may include, as an example, 100 parts by weight of a resin marketed under the tradename Adiprene L-lO, 9 parts by weight of cast-or oil and 3.2 lparts by weight 1,4-butanediol. The Adiprene resin is a polyurethane-type resin and consists of a linear polymer of 1,-4-butanediol and toluene diisocyanate (primarily 2,4-to1uene diisocyanate). Other suitable resilient elastomeric coating compositions are known to and will be apparent to those in the art and may include resilient material and synthetic rubber, such as butyl rubber.

The above-mentioned resilient coating materials are merely illustrative of coating materials which may be used to' provide coated particles in accordance herewith. It to be understood that any coating materials having sufficient elasticity to be deformable under impact of a bowling ball are usable. More advantageously, the coating material should be sufficiently resilient to maintain the outer shape of the bowling pin after repeated impacts. The coating material is soft and more elastic than the hard core and is preferably resistant to cold fiow. Neither upper nor lower limits have been found for moduli of elasticity of usable material. However, the modulus of elasticity should be substantial-ly lower than that of the hard core material, and any softer materittls should be usable so long as the property of resiliency is retained.

The coating material may be applied to the pin core as an uncured liquid mixture of resin ingredients and can thereafter be cured for a time and temperature suflicient to solidify the resin mixture, depending on the elastomeric material used. For example, the specific coating mixture of Adiprene L-lOO, castor oil and l,4butanediol is cured for about 3 hours at about 285 F. :to a Shore A 46 hardness. The bowling pin core and coating was then turned to a size slightly smaller than the regulation bowling pin size and outer protective coating 17a was applied to bring the pin up to regulation size. Coating l7a functions to protect the pin against discoloration, e.g. by dirt, and may serve to reduce the coefficient of friction on the outer pin surface. The outer coating may be a conventional plastic coating for bowling pins, e.g. nitrocellulose or ethylcellulose lacquers, cellulose acetate and/or butyrate, polyuretha-ne lacquer, etc.

Referring now to FIGURE 2 of the drawings, there is illustrated a particular preferred embodiment of a bowling pin in accordance with the present invention. Pin Z includes hollow metal core 2l having an indented bracing portion 25 opposing ball impact forces. Bracing position 25 forms an annular indentation 'of the core outer surface in the belly region and permits inclusion of greater thickness of inner resilient coating material over annular space 28. The greater thickness of resilient material decreases iiexual fatigue of the resilient coating and also dampens sound when the pin is struck by a bowling ball. The indentation may conveniently be provided by molding or turning to provide annular concave surface 26. Surface 26 is circumferential and defines the exterior of the core in the impact area of the belly region and opposes circumferential bracing portion 25. A circumferential space 28 is provided between surface 26 and resilient coating 27. Space 28 is formed generally of a `groove in the inner surface of coating 27 facing concave surface 26. The configuration and thickness of resilient coating 27 enclosing space 2S is such as to permit the application of an approximately uniform protective coating 27a over the resilient coating to bring the core and coating material up to regulation pin size.

The material of coating 27 is the same material as used in the coating 17 of pin 16 lof FIGURE 1 and the outer protective coating 27a is an ethylcellulose lacquer. Thus, pin is provided with a coating over the core 'and void or space 18 or 28, which coating has high internal tenacity, including good flexure characteristics, good resiliency, high fatigue life, and low cold flow properties.

the coating material as described above.

The circumferential pocket or void may be formed as desired by those in the art. However, we have found a conveniently formed void which may advantageously be included between the core and coating. Accordingly the pocket or voidcan be a cavity between the core and coating formed by the inclusion of a non-structural very low density foam such as 2-4 lb./cu. ft. polyethylene, Adiprene, butyl rubber, etc., having structural properties less than those needed for cushioning the impact of the inner coating against the pin core under normal ball impact conditions. The foam may be destroyed in situ if desired to leave one circumferential continuous pocket or void between the cover and core. Destroyed foam is indicated at 15a and 25u in FGURES l and 2 of the drawings. However, even where the foam is not destroyed during manufacture of the pin, the foam functions essentially as a void or continuous pocket and is therefore considered as a void or pocket.

The manufacture of the bowling pins of FIGURES l and 2 may be apparent from the above descriptions. However, as a guide to those in the art, the pin of FIG- URE l was manufactured by turning the hard hollow metal core to provide groove i6, placing a band of nonstructural very low density foam, e.g. having a density of 2-4 lbs/cu. ft., in the groove and thereafter coating the core with the resilient coating material and curing The low density foam prevents the resilient inner coating material from adhering to the core in the groove, thereby causing the coating to spa-n the groove when applied. During curing, the low density foam is usually destroyed, eg. by melting in the caseof a polyethylene foam (NLP. about F.) or other low melting foam or by thermal degradation of higher melting foams, at the curing temperature of the resilient coating. However, because the foam used is substantially non-structural and predominates substantially in air, even in instances where the foam is not destroyed during the curing operation, the foam can be considered as merely a circumferential pocket or void, being incapable of cushioning ball impacts and thereby providing a desired bottoming out of the resilient material against the core under impact. In the variation of FIGURE 2, core 21 was molded to provide annular concave surface 26. A preformed mass of the non-structural foam material 28 was then applied to surface 26 with a suitable adhesive, and the core and foam material was then coated with the resilient coating composition, cured and finished as described above.

It is apparent from the foregoing that the present invention has provided new and useful bowling pins which include intentional voids between the coating or cover and core in the impact region. In the prior art, voids between the coating and core have occurred during use of plasticcoated Wood core pins as described by W. F. Grawey in U.S. Patent 2,978,375, patented April 4, 1961. However, such voids are localized voids which have been undesirable and entirely unintentional. The circumferential pockets or voids in the bowling pins of this invention enclose nonsolid materials such as air or other gases and provide for additional deformation of the pin surface in the impact area. Preferably the voids extend into the core or normal core configuration so that a portion of the core, rather than a portion of the coating, is replaced by the voids to retain acceptable appearance and sound characteristics in the pin. The voids or pockets in the present pins function to improve score-ability of the pin on both thin and heavy hits. On a glancing blow, the force of the bowling ball is used over a Vlonger period of time thereby increasing acceleration of the pin. During dead-on or full-hits, the coating bottoms out against the core giving good force transmission from the ball to the core. In either event, the increased displacement or bottoming out of the coating and the pin surface appears to insure no appreciable decrease in the .pick-off properties of the pin, and such properties may even be improved. The provision of the void projecting more into the coating than the core may I be advantageous in giving greater access of the void to the deformed resilient coating material under impact conditions and may serve to enhance the bottoming out action. Of course, the size and positioning of the void in the belly region may be adjusted as desired by those in the art.

Conventionally, regulation bowling pins have been constructed essentially of a hard maple core with a plastic coating over the core. The American Bowling Congress, the major regulatory body with respect to bowling pin specifications, has prescribed that regulation pins shall be of sound, hard maple. With dwindling supplies of suitable maple stock and resulting increased costs of such stock, it would be highly desirable to enable substitution of other hard materials for the maple core. Hollow metal cores have shown much promise along this line. However, hollow metal cores when coated with plastic usually do not have the same scoring characteristics as a maple core pin, e.g., the score obtained with such a pin may be either higher or lower than the score range for a cornparable maple core pin. The use of circumferential pockets between the coating and core of a pin in accordance herewith may be essentially advantageous as applied to hollow metal core pins for improving their scoring characteristics, which hollow metal core pins often show very definite scoring weaknesses in both the thin and heavy-hit areas in the game of tenpins. Addition-ally, the bottoming out effect permits transfer of force from ball impact over a longer period of time, resulting in improved durability and improved sound characteristics.

We claim:

1. A bowling pin having a hard metal core and intended to be subjected to impact forces, a flexible cover over the core and extending from the pin base through the pin head, and a circumferential generally void cavity between the core and cover, the limits of said cavity being dened by the core and cover at the `ball impact area of said pin with said cover Secured directly to the metal surface of said core beyond the limits of said cavity.

2. The bowling pin of claim 1 wherein said cavity is defined essentially by walls of an annular groove in said core and by said cover completely spanning said groove.

3. The bowling pin of claim 1 wherein said cavity extends outwardly as an annular groove in said liexible coating.

4. The bowling pin of claim 3 wherein the outer surface of the core is of concave configuration across the ball impact area.

5. The bowling pin of claim 1 wherein said cavity contains the residue of destroyed very low density foamed plastic.

References Cited by the Examiner UNITED STATES PATENTS 679,205 7/ 1901 Barrett 273-82 1,422,232 7/ 1922 Stanley. 2,166,950 7/1939 German et al 273-82 3,018,106 1/1962 Satchell et al. 273-82 3,138,380 6/1964 Satchell et al 273-82 FOREIGN PATETS 641,073 5/1962 Canada.

RICHARD C. PINKHAM, Primary Examiner.

DELBERT B. LOWE, Examiner. 

1. A BOWLING PIN HAVING A HARD METAL CORE AND INTENDED TO BE SUBJECTED TO IMPACT FORCES, A FLEXIBLE COVER OVER THE CORE AND EXTENDING FROM THE PIN BASE THROUGH THE PIN HEAD, AND A CIRCUMFERENTIAL GENERALLY VOID CAVITY BETWEEN THE CORE AND COVER, THE LIMITS OF SAID CAVITY BEING DEFINED BY THE CORE AND COVER AT THE BALL IMPACT AREA OF SAID PIN WITH SAID COVER SECURED DIRECTLY TO THE METAL SURFACE OF SAID CORE BEYOND THE LIMITS OF SAID CAVITY. 